Shot dead: Police said they negotiated with McCarroll (l) before using deadly force (Image: St Louis County Police)

In the case of McCarroll, officers claim they were forced to respond with deadly force after trying to negotiate with the armed man for nearly half an hour.

They said they opened fire after attempting to disarm him and diffuse the situation.

A spokesman said: "The officers resorted to less lethal force to try and bring the incident to a safe conclusion with no loss of life, but this individual made the decision to refuse these attempts and charge at officers with a deadly weapon."

Police released a video of the incident, in which officers can be heard attempting to pacify McCarroll and convince him to give up his weapon.

However, McCarroll can not be seen or heard in the grainy footage.

"Do me a favor and just drop the knife and walk over here to tell me what's going on," says one officer.

"We are not here to harm you."

Armed: Police said McCarroll charged at them with a knife and a copy of the Bible (Image: St Louis County Police / You Tube / Getty)

The latest shooting comes amidst intense scrutiny over US policing tactics following a series of controversial shootings, mainly involving African American men.